18265421 has 2 divisors, whose sum is σ = 18265422. Its totient is φ = 18265420.

The previous prime is 18265393. The next prime is 18265451. The reversal of 18265421 is 12456281.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17732521 + 532900 = 4211^2 + 730^2 .

It is an emirp because it is prime and its reverse (12456281) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18265421 - 2¹⁰ = 18264397 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18265451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9132710 + 9132711.

It is an arithmetic number, because the mean of its divisors is an integer number (9132711).

Almost surely, 2^18265421 is an apocalyptic number.

It is an amenable number.

18265421 is a deficient number, since it is larger than the sum of its proper divisors (1).

18265421 is an equidigital number, since it uses as much as digits as its factorization.

18265421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3840, while the sum is 29.

The square root of 18265421 is about 4273.8063830735. The cubic root of 18265421 is about 263.3560070562.

The spelling of 18265421 in words is "eighteen million, two hundred sixty-five thousand, four hundred twenty-one".